Light emitting device

ABSTRACT

A light emitting device including a substrate having a first surface and a second surface opposing the first surface, at least one of the first and second surfaces having a concave part extending to the inside of the substrate, a plurality of light emitting cells disposed on the first surface of the substrate, and a light shielding layer filling at least a portion of the concave part and disposed between the plurality of light emitting cells.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of U.S.Provisional Patent Application No. 62/741,924, filed on Oct. 5, 2018,which is hereby incorporated by reference for all purposes as if fullyset forth herein.

BACKGROUND Field

Exemplary embodiments of the present disclosure relate to a lightemitting device, and more particularly, to a light emitting deviceincluding a plurality of light emitting cells.

Discussion of the Background

Light emitting diodes are widely used as inorganic light sources invarious fields, such as display devices, vehicle lamps and generallighting. Light emitting diodes are rapidly replacing existing lightsources due to their longer lifetime, lower power consumption, andfaster response speed over conventional light sources.

As recently light emitting diodes are being developed to have lightweight, thinness, compactness, and miniaturization, so as to be used asbacklight sources of various display devices, such as a mobile phone, acolor mixing may occur between neighboring light emitting cells.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Light emitting devices constructed according to exemplary embodiments ofthe invention are capable of preventing color mixing to provideexcellent color reproducibility.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

A light emitting device according to an exemplary embodiment includes asubstrate having a first surface and a second surface opposing the firstsurface, at least one of the first and second surfaces having a concavepart extending to the inside of the substrate, a plurality of lightemitting cells disposed on the first surface of the substrate, and alight shielding layer filling at least a portion of the concave part anddisposed between the plurality of light emitting cells.

At least one of the light emitting cells may have a first light emittingpart, a second light emitting part, and a third light emitting partvertically stacked one over another.

The light emitting device may further include a common pad, a first pad,a second pad, and a third pad disposed on the at least one lightemitting cell, in which the common pad may be electrically connected tothe first, second, and third light emitting parts in common, and thefirst, second, and third pads may be electrically connected to thefirst, second, and third light emitting parts, respectively.

The light shielding layer may include at least one of Ti, Ni, Al, Ag,Cr, a photoresist, epoxy, PDMS, and a black matrix.

The light shielding layer may be disposed on the first surface of thesubstrate, and the light shielding layer may be disposed between thelight emitting cells on the first surface of the substrate, and has atop surface coplanar with a top surface of each of the light emittingcells.

The light emitting device may further include pads disposed on the lightshielding layer and electrically coupled with the light emitting cells,respectively.

The light emitting device may further include an insulating layerdisposed on the light shielding layer, through electrodes passingthrough the insulating layer and the light shielding layer, andelectrically coupled with the light emitting cells, respectively, andpads disposed on the insulating layer and electrically coupled with thethrough electrodes.

The concave part may include a first concave part extending from thefirst surface of the substrate to the inside of the substrate, and asecond concave part extending from the second surface of the substrateto the inside of the substrate, and the light shielding layer mayinclude a first light shielding layer filling at least a portion of thefirst concave part and a second light shielding layer filling at least aportion of the second concave part.

One end of the first light shielding layer and one end of the secondlight shielding layer may overlap with each other.

The first light shielding layer may include a vertical part extendingalong a first direction and a horizontal part extending along a seconddirection crossing the first direction, and the second light shieldinglayer may include a plurality of vertical parts extending along thefirst direction and parallel to each other, and a plurality ofhorizontal parts extending along the second direction.

The vertical part of the first light shielding layer may be disposedbetween the vertical parts of the second light shielding layer, and thehorizontal part of the first light shielding layer may be disposedbetween the horizontal parts of the second light shielding layer.

The substrate may include cell areas in which the plurality of lightemitting cells are disposed, and a peripheral area adjacent to the cellareas, the cell areas may include light emitting areas defined by thefirst light shielding layer and the second light shielding layer,respectively, and each light emitting area may be smaller than each cellarea.

Portions of the substrate corresponding to the light emitting areas mayhave a surface roughness.

The light emitting device may further include through electrodes passingthrough the substrate and electrically coupling the light shieldinglayer and the light emitting cells, in which the light shielding layermay be disposed on the second surface of the substrate.

The light shielding layer may include at least one of Ti, Ni, Al, Ag,and Cr.

The light emitting device may further include a pad disposed between thefirst surface of the substrate and the light emitting cells, andelectrically coupled with the light emitting cells.

The substrate may include cell areas in which the plurality of lightemitting cells are disposed, and a peripheral area adjacent to the cellareas, the cell areas may include light emitting areas defined by thelight shielding layer, respectively, and each light emitting area may besmaller than each cell area.

Portions of the substrate corresponding to the light emitting areas mayhave a surface roughness.

The concave part may have at least one of substantially a V-shapedstructure, substantially a polygonal structure in which the firstsurface or the second surface of the substrate is opened, andsubstantially a U-shaped structure.

The light shielding layer may fill at least a portion of the concavepart and extends to the first surface or the second surface of thesubstrate.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concept, and, together with thedescription, serve to explain principles of the inventive concept.

FIG. 1A is a schematic top view of a light emitting device according toan exemplary embodiment.

FIG. 1B is a cross-sectional view taken along line A-A′ of FIG. 1A.

FIG. 1C is an enlarged view of the concave part of the light emittingdevice of FIG. 1A.

FIGS. 1D, 1E, and 1F are enlarged views of the concave part of the lightemitting device according to exemplary embodiments.

FIGS. 2A, 2B, 2C, and 2D are cross-sectional views of the lightshielding layers according to an exemplary embodiment.

FIG. 3A is a schematic top view of a light emitting device according toanother exemplary embodiment.

FIG. 3B is a cross-sectional view taken along line A-A′ of FIG. 3A.

FIG. 4A is a schematic top view of a light emitting device according toanother exemplary embodiment.

FIG. 4B is a cross-sectional view taken along line A-A′ of FIG. 4A.

FIG. 5A is a schematic top view of a light emitting device according toanother exemplary embodiment.

FIG. 5B is a cross-sectional view taken along line A-A′ of FIG. 5A.

FIG. 6A is a schematic top view of a light emitting device according toanother exemplary embodiment.

FIG. 6B is a cross-sectional view taken along line A-A′ of FIG. 6A.

FIGS. 7A and 7B are schematic top views of a light emitting deviceaccording to another exemplary embodiment.

FIG. 7C is a cross-sectional view taken along line A-A′ of FIG. 7A.

FIGS. 8A and 8B are schematic top views of a light emitting deviceaccording to another exemplary embodiment.

FIG. 8C is a cross-sectional view taken along line A-A′ of FIG. 8A.

FIGS. 9A and 9B are schematic top views of a light emitting deviceaccording to another exemplary embodiment.

FIG. 9C is a cross-sectional view taken along line A-A′ of FIG. 9A.

FIGS. 10A and 10B are schematic top views of a light emitting deviceaccording to another exemplary embodiment.

FIG. 10C is a cross-sectional view taken along line A-A′ of FIG. 10A.

FIG. 11A is a schematic top view of a light emitting device according toanother exemplary embodiment.

FIG. 11B is a cross-sectional view taken along line A-A′ of FIG. 11A.

FIGS. 12A, 13A, 14A, 15A, and 16A are top views to illustrate a methodfor manufacturing a light emitting device according to an exemplaryembodiment.

FIGS. 12B, 13B, 14B, 15B, and 16B are cross-sectional views taken alongline A-A′ of corresponding ones of FIGS. 12A to 16A.

FIGS. 17A, 18A, and 19A are top views to illustrate a method formanufacturing a light emitting device according to another exemplaryembodiment.

FIGS. 17B, 18B, and 19B are cross-sectional views taken along line A-A′of corresponding ones of FIGS. 17A to 19A.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various exemplary embodiments. Further, various exemplaryembodiments may be different, but do not have to be exclusive. Forexample, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

Hereinafter, a light emitting device will be described below withreference to the accompanying drawings through various exemplaryembodiments.

FIG. 1A is a schematic top view of a light emitting device according toan exemplary embodiment, and FIG. 1B is a cross-sectional view takenalong line A-A′ of FIG. 1A. FIG. 1C is an enlarged view of the concavepart 106 of the light emitting device illustrated in FIG. 1B, and FIGS.1D to 1F are modifications of the concave part 106 of FIG. 1C accordingto exemplary embodiments.

Referring to FIGS. 1A to 1C, a light emitting device may include asubstrate 100 and a plurality of light emitting cells LEC_1 and LEC_2disposed on the substrate 100.

The substrate 100 may be capable of growing a gallium nitride-basedsemiconductor layer thereon, and may include a sapphire (Al₂O₃), asilicon carbide (SiC), a gallium nitride (GaN), an indium galliumnitride (InGaN), an aluminum gallium nitride (AlGaN), an aluminumnitride (AlN), a gallium oxide (Ga₂O₃), a gallium arsenic (GaAs), orsilicon (Si). In some exemplary embodiments, the substrate 100 may beflexible, or include a circuit therein.

The substrate 100 may have a first surface 102, on which the lightemitting cells LEC_1 and LEC_2 are disposed, and a second surface 104opposing the first surface 102. The second surface 204 of the substrate100 may be a light emitting surface of light generated from the lightemitting cells LEC_1 and LEC_2.

According to an exemplary embodiment, the substrate 100 may have athickness as thin as possible. This is because the substrate 100 mayfunction as a light guide plate, through which light generated from thelight emitting cells LEC_1 and LEC_2 may be guided. As such, in order toprevent the substrate 100 functioning as a light guide plate, thesubstrate 100 may have a thickness as thin as possible. For example, thesubstrate 100 may have a thickness of about 80 μm to about 200 μm.

By etching the substrate 100, the first surface 102 of the substrate 100may be formed with a concave part 106, which extends from the firstsurface 102 to the inside of the substrate 100. The concave part 106 mayinclude a vertical part VL extending in a first direction DR1, and ahorizontal part HL extending in a second direction DR2 intersecting thefirst direction DR1. For example, the vertical part VL and thehorizontal part HL may cross with each other.

Referring to FIG. 1C, the concave part 106 may have substantially aV-shaped structure, which has two sides converging from the firstsurface 102 of the substrate 100 to a point inside the substrate 100.The depth DT of the concave part 106 may be about ⅓ to about ⅔ of thethickness DT_S of the substrate 100. For example, when the substrate 100has the thickness DT_S of 80 μm to 100 μm, the concave part 106 may havethe depth DT of 25 μm to 70 μm. The longest width WT between the twosides of the concave part 106 may be about 20 μm to about 30 μm. Theangle β between the two sides of the concave part 106 may be about 40 toabout 80 degrees.

The inventive concepts are not limited to one particular shape of theconcave part 106, and in some exemplary embodiments, the concave part106 may have various structures other than the substantially V-shapedstructure. Referring to FIG. 1D, the concave part 106 according toanother exemplary embodiment may include two vertical surfaces, whichextend from the first surface 102 of the substrate 100 to the inside ofthe substrate 100 and are parallel to each other, and a horizontalsurface connecting the vertical surfaces. In a cross-sectional view, theconcave part 106 may have substantially an open square structure, inwhich a side corresponding to the first surface 102 of the substrate 100is opened. Referring to FIG. 1E, the concave part 106 according toanother exemplary embodiment may include two vertical surfaces, whichextend from the first surface 102 of the substrate 100 to the inside ofthe substrate 100 and are parallel to each other, and two surfacesconverging into a point between the two vertical surfaces. In across-sectional view, the concave part 106 may have substantially anopen pentagon structure, in which a side corresponding to the firstsurface 102 of the substrate 100 is opened. Referring to FIG. 1F, theconcave part 106 according to another exemplary embodiment may extendfrom the first surface 102 of the substrate 100 to the inside of thesubstrate 100, and have a curved surface. In a cross-sectional view, theconcave part 106 may have substantially a U-shaped structure. It is tobe noted that, however, the inventive concepts are not limited to oneparticular shape of the concave part 106, and in some exemplaryembodiments, the concave part 106 may have various structures other thanthose described above.

Referring back to FIGS. 1A and 1B, a light shielding layer 140 may bedisposed at least in a portion of the concave part 106. Between the twoneighboring light emitting cells LEC_1 and LEC_2, for example, a firstlight emitting cell LEC_1 and a second light emitting cell LEC_2, thelight shielding layer 140 may reflect light generated in the first lightemitting cell LEC_1 toward the first light emitting cell LEC_1, orshield or absorb light generated in the first light emitting cell LEC_1,such that light generated in the first light emitting cell LEC_1 doesnot exert an influence on the second light emitting cell LEC_2.Similarly, the light shielding layer 140 may reflect light generated inthe second light emitting cell LEC_2 toward the second light emittingcell LEC_2, or shield or absorb light generated in the second lightemitting cell LEC_2, such that light generated in the second lightemitting cell LEC_2 does not exert an influence on the first lightemitting cell LEC_1. For example, the light shielding layer 140 mayinclude metal, such as Ti, Ni, Al, Ag and Cr, or may include a material,such as a photoresist, epoxy, PDMS (polydimethylsiloxane), and a blackmatrix.

Hereinafter, the structure of the light shielding layer 140 will bedescribed as being formed in the concave part 106 illustrated in FIG.1C.

FIGS. 2A to 2D are cross-sectional views illustrating the structures oflight shielding layers according to exemplary embodiments.

Referring to FIG. 2A, the light shielding layer 140 according to anexemplary embodiment may not completely fill the concave part 106, andmay be conformally formed continuously along the inner sidewall of theconcave part 106. Referring to FIG. 2B, the light shielding layer 140according to another exemplary embodiment may not completely fill theconcave part 106, may be conformally formed on the inner sidewall of theconcave part 106, and may extend onto the first surface 102 of thesubstrate 100 to cover at least a portion of the first surface 102 ofthe substrate 100. Referring to FIG. 2C, the light shielding layer 140according to another exemplary embodiment may completely fill theconcave part 106, and may have a top surface coplanar with the firstsurface 102 of the substrate 100. Referring to FIG. 2D, the lightshielding layer 140 according to another exemplary embodiment maycompletely fill the concave part 106, and may extend onto the firstsurface 102 of the substrate 100 to cover at least a portion of thefirst surface 102 of the substrate 100.

While the structure of the light shielding layer 140 has been describedwith reference to the structure of the concave part 106 illustrated inFIG. 1C, in some exemplary embodiments, the light shielding layer 140according to exemplary embodiments may be applied to one of thestructures of the concave part 106 illustrated in FIGS. 1D to 1F, andthus, repeated descriptions thereof will be omitted to avoid redundancy.

Referring back to FIGS. 1A and 1B, the light emitting cells LEC_1 andLEC_2 may be disposed on the substrate 100 and be separated from eachother by a predetermined distance. The separation distance of the lightemitting cells LEC_1 and LEC_2 may be changed depending on an apparatusto which the light emitting device is to be mounted.

According to an exemplary embodiment, each of the light emitting cellsLEC_1 and LEC_2 may have a beam angle α of about 105 to about 150degrees. As described above, the separation distance between the lightemitting cells LEC_1 and LEC_2 may be changed depending on an apparatus,to which the light emitting cells LEC_1 and LEC_2 are to be mounted. Assuch, the concave part 106, which is formed with the light shieldinglayer 140, may be disposed in the substrate 100 between the first lightemitting cell LEC_1 and the second light emitting cell LEC_2, each ofwhich has the beam angle α of about 105 to about 150 degrees. Theconcave part 106 may be disposed at a position where light generated inthe first light emitting cell LEC_1 (or the second light emitting cellLEC_2) is to be reflected, shielded, or absorbed by the light shieldinglayer 140 not to exert an influence on the second light emitting cellLEC_2 (or the first light emitting cell LEC_1).

The plurality of light emitting cells LEC_1 and LEC_2 disposed on thesubstrate 100 may be a unit, which is to be mounted to a targetapparatus at one time. For example, when the light emitting device isformed with four light emitting cells LEC_1 and LEC_2 on the substrate100, the four light emitting cells LEC_1 and LEC_2 may be mounted to atarget apparatus through one process. While four light emitting cellsLEC_1 and LEC_2 have been exemplarily described, it is to be noted thatthe inventive concepts are not limited to one particular number of thelight emitting cells LEC_1 and LEC_2 in a light emitting device.

Each of the light emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114, and an ohmic layer 116. Thefirst conductivity-type semiconductor layer 110 may be an n-typesemiconductor layer, which includes a Si-doped gallium nitride-basedsemiconductor layer. The second conductivity-type semiconductor layer114 may be a p-type semiconductor layer, which includes a Mg-dopedgallium nitride-based semiconductor layer. Alternatively, the firstconductivity-type semiconductor layer 110 may be a p-type semiconductorlayer, and the second conductivity-type semiconductor layer 114 may bean n-type semiconductor layer. The active layer 112 may include amulti-quantum well (MQW), and the composition ratio thereof may bedetermined to emit light of a desired peak wavelength. As the ohmiclayer 116, a transparent conductive oxide (TCO), such as zinc oxide(ZnO), indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zincindium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO),fluorine-doped tin oxide (FTO), gallium-doped zinc oxide (GZO),aluminum-doped zinc oxide (AZO), or others may be used.

Each of the light emitting cells LEC_1 and LEC_2 may further include afirst pad 120, which is electrically coupled with the firstconductivity-type semiconductor layer 110, and a second pad 130, whichis electrically coupled with the ohmic layer 116. Each of the first pad120 and the second pad 130 may include at least one of Au, Ti, Ni, Cr,and Al.

FIG. 3A is a schematic top view of a light emitting device according toanother exemplary embodiment, and FIG. 3B is a cross-sectional viewtaken along line A-A′ of FIG. 3A.

Referring to FIGS. 3A and 3B, the light emitting device according to theillustrated exemplary embodiment is similar to the light emitting deviceillustrated with reference to FIGS. 1A and 1B, however, each of thelight emitting cells LEC_1 and LEC_2 according to the illustratedexemplary embodiment includes a first light emitting part LEC_1_1 orLEC_2_1, a second light emitting part LEC_1_2 or LEC_2_2, and a thirdlight emitting part LEC_1_3 or LEC_2_3, which are vertically stacked. Assuch, the differences of the light emitting device will be mainlydescribed hereinafter in order to avoid redundancy.

When the second surface 104 of the substrate 100 is a light emittingsurface, the first light emitting parts LEC_1_1 and LEC_2_1 may generatelight having the shortest wavelength, the second light emitting partsLEC_1_2 and LEC_2_2 may generate light having a wavelength longer thanthe wavelength of light generated in the first light emitting partsLEC_1_1 and LEC_2_1 and shorter than the wavelength of light generatedin the third light emitting parts LEC_1_3 and LEC_2_3, and the thirdlight emitting parts LEC_1_3 and LEC_2_3 may generate light having thelongest wavelength. For example, the first light emitting parts LEC_1_1and LEC_2_1 may generate blue light, the second light emitting partsLEC_1_2 and LEC_2_2 may generate green light, and the third lightemitting parts LEC_1_3 and LEC_2_3 may emit red light. However, theinventive concepts are not limited thereto. For example, in someexemplary embodiments, the second light emitting parts LEC_1_2 andLEC_2_2 may emit light having a wavelength shorter than the wavelengthof light emitted from the first light emitting parts LEC_1_1 andLEC_2_1. The first light emitting parts LEC_1_1 and LEC_2_1 may includea first n-type semiconductor layer, a first active layer, a first p-typesemiconductor layer, and a first ohmic layer. The second light emittingparts LEC_1_2 and LEC_2_2 may include a second n-type semiconductorlayer, a second active layer, a second p-type semiconductor layer, and asecond ohmic layer. The third light emitting parts LEC_1_3 and LEC_2_3may include a third n-type semiconductor layer, a third active layer, athird p-type semiconductor layer, and a third ohmic layer. Each of thefirst n-type semiconductor layer, the second n-type semiconductor layer,and the third n-type semiconductor layer may be a Si-doped galliumnitride-based semiconductor layer. Each of the first p-typesemiconductor layer, the second p-type semiconductor layer and the thirdp-type semiconductor layer may be a Mg-doped gallium nitride-basedsemiconductor layer. Each of the first active layer, the second activelayer, and the third active layer may include a multi-quantum well(MQW), and the composition ratio thereof may be determined to emit lightof a desired peak wavelength. Each of the first ohmic layer, the secondohmic layer, and the third ohmic layer may include transparentconductive oxide, such as ZnO, ITO, ZITO, ZIO, GIO, ZTO, FTO, GZO, AZO,or others.

Each of the light emitting cells LEC_1 and LEC_2 may further include acommon pad 120 a, which electrically couples the first ohmic layer, thesecond ohmic layer and the third ohmic layer in common, a first pad 120b that is electrically coupled with the first n-type semiconductorlayer, a second pad 120 c that is electrically coupled with the secondn-type semiconductor layer, and a third pad 120 d that is electricallycoupled with the third n-type semiconductor layer. Alternatively, eachof the light emitting cells LEC_1 and LEC_2 may further include a commonpad 120 a, which electrically couples the first n-type semiconductorlayer, the second n-type semiconductor layer, and the third n-typesemiconductor layer in common, a first pad 120 b that is electricallycoupled with the first ohmic layer, a second pad 120 c that iselectrically coupled with the second ohmic layer, and a third pad 120 dthat is electrically coupled with the third ohmic layer.

For example, when each of the light emitting cells LEC_1 and LEC_2includes the first light emitting part LEC_1_1 or LEC_2_1, the secondlight emitting part LEC_1_2 or LEC_2_2, and the third light emittingpart LEC_1_3 or LEC_2_3 which are vertically stacked, the third lightemitting part LEC_1_3 or LEC_2_3 may expose at least a portion of thesecond light emitting part LEC_1_2 or LEC_2_2, and the second lightemitting part LEC_1_2 or LEC_2_2 may expose at least a portion of thefirst light emitting part LEC_1_1 or LEC_2_1, such that the common pad120 a, the first pad 120 b, the second pad 120 c and the third pad 120 dare electrically coupled with the first light emitting part LEC_1_1 orLEC_2_1, the second light emitting part LEC_1_2 or LEC_2_2, and thethird light emitting part LEC_1_3 or LEC_2_3. In this case, the thirdlight emitting part LEC_1_3 or LEC_2_3 may be smaller than the secondlight emitting part LEC_1_2 or LEC_2_2, and the second light emittingpart LEC_1_2 or LEC_2_2 may be smaller than the first light emittingpart LEC_1_1 or LEC_2_1.

As another example, the first light emitting part LEC_1_1 or LEC_2_1,the second light emitting part LEC_1_2 or LEC_2_2, and the third lightemitting part LEC_1_3 or LEC_2_3 may have substantially the same size,and each of the light emitting cells LEC_1 and LEC_2 may further includea plurality of via structures, which electrically couple the common pad120 a, the first pad 120 b, the second pad 120 c, and the third pad 120d with the first light emitting part LEC_1_1 or LEC_2_1, the secondlight emitting part LEC_1_2 or LEC_2_2, and the third light emittingpart LEC_1_3 or LEC_2_3.

As yet another example, the first light emitting part LEC_1_1 or LEC_2_1and the second light emitting part LEC_1_2 or LEC_2_2 may havesubstantially the same size, and the third light emitting part LEC_1_3or LEC_2_3 may expose at least a portion of the second light emittingpart LEC_1_2 or LEC_2_2, such that the common pad 120 a, the first pad120 b, the second pad 120 c, and the third pad 120 d are electricallycoupled with the first light emitting part LEC_1_1 or LEC_2_1, thesecond light emitting part LEC_1_2 or LEC_2_2, and the third lightemitting part LEC_1_3 or LEC_2_3. In this case, the first light emittingpart LEC_1_1 or LEC_2_1 and the second light emitting part LEC_1_2 orLEC_2_2 may be electrically coupled with the common pad 120 a, the firstpad 120 b, and the second pad 120 c by a plurality of via structures.

In the illustrated exemplary embodiment, the concave part 106 and thelight shielding layer 140 described reference with FIGS. 1A through 1F,as well as FIGS. 2A through 2D, may be similarly employed.

The light emitting device according to the illustrated exemplaryembodiment is described as including three vertically stacked lightemitting parts, however, the inventive concepts are not limited thereto.In some exemplary embodiments, a light emitting device may include twolight emitting parts or more than four light emitting parts, which maybe vertically stacked.

Further, each light emitting cell may have light emitting parts that arevertically stacked, but the inventive concepts are not limited thereto,and in some exemplary embodiments, at least one light emitting cell mayhave a single light emitting part.

The vertically stacked light emitting parts according to the illustratedexemplary embodiment may be applied to light emitting cells of variousexemplary embodiments to be described later.

FIG. 4A is a schematic top view of a light emitting device according toanother exemplary embodiment, and FIG. 4B is a cross-sectional viewtaken along line A-A′ of FIG. 4A. FIG. 5A is a schematic top view of alight emitting device according to still another exemplary embodiment,and FIG. 5B is a cross-sectional view taken along line A-A′ of FIG. 5A.

Referring to FIGS. 4A, 4B, 5A and 5B, a light emitting device mayinclude a substrate 100 and a plurality of light emitting cells LEC_1and LEC_2 disposed on the substrate 100.

The substrate 100 may have a first surface 102, on which the lightemitting cells LEC_1 and LEC_2 are disposed, and a second surface 104opposing the first surface 102. The first surface 102 of the substrate100 may be formed with a concave part 106, which extends from the firstsurface 102 to the inside of the substrate 100. Since the substrate 100and the concave part 106 are substantially the same as those describedabove with reference to FIGS. 1A and 1B, repeated descriptions thereofwill be omitted.

The first concave part 106 according to the illustrated exemplaryembodiment may have the structure of the concave part 106 describedabove with reference to FIGS. 1C to 1F, without being limited thereto.

The light emitting cells LEC_1 and LEC_2 may be disposed on the firstsurface 102 of the substrate 100 and be separated by a predetermineddistance. Each of the light emitting cells LEC_1 and LEC_2 may include afirst conductivity-type semiconductor layer 110, an active layer 112, asecond conductivity-type semiconductor layer 114, and an ohmic layer116, which are vertically stacked, a first pad 120 electrically coupledwith the first conductivity-type semiconductor layer 110, and a secondpad 130 electrically coupled with the ohmic layer 116.

A light shielding layer 140 may be disposed to fill the concave part 106and cover the light emitting cells LEC_1 and LEC_2 on the first surface102. The light shielding layer 140 may include an insulating material,such as a photoresist, epoxy, PDMS, and a black matrix.

When light generated in respective active layers 112 of the lightemitting cells LEC_1 and LEC_2 are emitted in all directions, the lightshielding layer 140 may be disposed between the light emitting cellsLEC_1 and LEC_2 and prevent the lights from being mixed. In particular,since the light shielding layer 140 is disposed between the neighboringlight emitting cells LEC_1 and LEC_2, for example, a first lightemitting cell LEC_1 and a second light emitting cell LEC_2, on the firstsurface 102 of the substrate 100, light generated in the active layer112 of the first light emitting cell LEC_1 may be radiated toward thefirst surface 102 of the substrate 100 while not exerting an influenceon the second light emitting cell LEC_2, and light generated in theactive layer 112 of the second light emitting cell LEC_2 may be radiatedtoward the first surface 102 of the substrate 100 while not exerting aninfluence on the first light emitting cell LEC_1. Although light of thefirst light emitting cell LEC_1 and light of the second light emittingcell LEC_2, which are emitted toward the substrate 100, may be radiatedin all directions in the substrate 100, light of the first lightemitting cell LEC_1 and light of the second light emitting cell LEC_2may be reflected, shielded, or absorbed by the light shielding layer 140filling the concave part 106, thereby not exerting an influence on eachother.

Further, as the light shielding layer 140 fills the concave part 106 andcover the light emitting cells LEC_1 and LEC_2, the substrate 100 havinga thin thickness may be prevented from being broken or damaged by anexternal shock.

Referring to FIGS. 4A and 4B, the top surface of the light shieldinglayer 140 may be substantially coplanar with the top surfaces of theohmic layers 116. The light shielding layer 140 may expose the ohmiclayers 116. For example, each first pad 120 may be buried by the lightshielding layer 140, and may be electrically coupled with a third pad124 disposed on the light shielding layer 140 through a throughelectrode 122 passing through the light shielding layer 140. The secondpad 130 may be disposed on the ohmic layer 116, which is exposed on thelight shielding layer 140.

Referring to FIGS. 5A and 5B, an insulating layer 150 may beadditionally disposed on the light shielding layer 140. The insulatinglayer 150 may include substantially the same material as the lightshielding layer 140. Alternatively, the insulating layer 150 may includea silicon oxide or a silicon nitride. The light emitting deviceaccording to the illustrated exemplary embodiment may further include afirst through electrode 122, which passes through the insulating layer150 and the light shielding layer 140 and is electrically coupled withthe first pad 120, a second through electrode 132, which passes throughthe insulating layer 150 and is electrically coupled with the second pad130, a third pad 124, which is disposed on the insulating layer 150 andis brought into electrical contact with the first through electrode 122,and a fourth pad 134, which is disposed on the insulating layer 150 andis brought into electrical contact with the second through electrode132. In this case, when the separation distance between the first pad120 and the second pad 130 is different from a separation distancerequired for an apparatus to which the light emitting device is to bemounted, the separation distance between the first pad 120 and thesecond pad 130 may be adjusted by changing the positions of the thirdpad 124, which is electrically coupled with the first pad 120, and thefourth pad 134, which is electrically coupled with the second pad 130.

Since the substrate 100, the concave part 106, the light shielding layer140, and the plurality of light emitting cells LEC_1 and LEC_2illustrated in FIGS. 4A, 4B, 5A and 5B are substantially the same asthose of the substrate 100, the concave part 106, the light shieldinglayer 140, and the plurality of light emitting cells LEC_1 and LEC_2described above with reference to FIGS. 1A to 1F and 2A to 2D, repeateddescriptions thereof will be omitted.

FIG. 6A is a schematic top view of a light emitting device according toanother exemplary embodiment, and FIG. 6B is a cross-sectional viewtaken along line A-A′ of FIG. 6A.

Referring to FIGS. 6A and 6B, a light emitting device may include asubstrate 100 and a plurality of light emitting cells LEC_1 and LEC_2disposed on the substrate 100.

The substrate 100 may have a first surface 102, on which the lightemitting cells LEC_1 and LEC_2 are disposed, and a second surface 104opposing the first surface 102. The first surface 102 of the substrate100 may be formed with a first concave part 106, which extends from thefirst surface 102 to the inside of the substrate 100. The first concavepart 106 may include a vertical part VL extending in a first directionDR1, and a horizontal part HL extending in a second direction DR2substantially perpendicular to the first direction DR1. In someexemplary embodiments, the vertical part VL and the horizontal part HLof the first concave part 106 may cross with each other. The secondsurface 104 of the substrate 100 may be formed with a second concavepart 108, which extends from the second surface 104 to the inside of thesubstrate 100. The second concave part 108 may include vertical parts VLextending in the first direction DR1 and are parallel to each other, andhorizontal parts HL extending in the second direction DR2 and areparallel to each other. In some exemplary embodiments, the verticalparts VL and the horizontal parts HL of the second concave part 108 maycross with each other.

When viewed from the top, the vertical part VL of the first concave part106 may not overlap with the vertical parts VL of the second concavepart 108, and the horizontal part HL of the first concave part 106 maynot overlap with the horizontal parts HL of the second concave part 108.For example, the vertical part VL of the first concave part 106 may bedisposed between the two neighboring vertical parts VL of the secondconcave part 108. The horizontal part HL of the first concave part 106may be disposed between the two neighboring horizontal parts HL of thesecond concave part 108. The second concave part 108 may be disposedmore adjacent to the light emitting cells LEC_1 and LEC_2 than the firstconcave part 106.

In a cross-sectional view, the vertical part VL of the first concavepart 106 may be disposed between the two neighboring vertical parts VLof the second concave part 108. Referring to the part A of FIG. 6B, theend of the vertical part VL of the first concave part 106 and the endsof the vertical parts VL of the second concave part 108 may overlap witheach other.

While each of the first concave part 106 and the second concave part 108is illustrated as having the structure described above with reference toFIG. 1C, however, the inventive concepts are not limited thereto. Forexample, in some exemplary embodiments, each of the first concave part106 and the second concave part 108 may have the structures of theconcave part 106 described above with reference to FIGS. 1D to 1F,without being limited thereto.

A first light shielding layer 140 may fill at least a portion of thefirst concave part 106. A second light shielding layer 145 may fill atleast a portion of the second concave part 108. Each of the first lightshielding layer 140 and the second light shielding layer 145 may includemetal, such as Ti, Ni, Al, Ag, and Cr, or may include a material, suchas a photoresist, epoxy, PDMS, and a black matrix. While each of thefirst light shielding layer 140 and the second light shielding layer 145is illustrated as having the structure of FIG. 2A, however, theinventive concepts are not limited thereto. For example, in someexemplary embodiments, each of the first light shielding layer 140 andthe second light shielding layer 145 may have the structures of thelight shielding layer 140 described above with reference to FIGS. 2B to2D, without being limited thereto.

Light generated from the plurality of light emitting cells LEC_1 andLEC_2, for example, a first light emitting cell LEC_1 and a second lightemitting cell LEC_2, may be reflected, shielded, or absorbed by thesecond light shielding layer 145, which is disposed adjacent to thelight emitting cells LEC_1 and LEC_2, and light passed through the spaceexcluding the second light shielding layer 145 may be reflected,shielded, or absorbed by the first light shielding layer 140. As thesecond light shielding layer 145 and the first light shielding layer 140are disposed between the first light emitting cell LEC_1 and the secondlight emitting cell LEC_2, light generated in the first light emittingcell LEC_1 may not exert an influence on the second light emitting cellLEC_2, and light generated in the second light emitting cell LEC_2 maynot exert an influence on the first light emitting cell LEC_1. In thismanner, it is possible to prevent mixture of light generated from aplurality of light emitting cells.

Since the substrate 100, the first concave part 106, the second concavepart 108, the first light shielding layer 140, the second lightshielding layer 145 and the plurality of light emitting cells LEC_1 andLEC_2 illustrated in FIGS. 6A and 6B are substantially the same as thoseof the substrate 100, the concave part 106, the light shielding layer140 and the plurality of light emitting cells LEC_1 and LEC_2 describedabove with reference to FIGS. 1A to 1F and 2A to 2D, repeateddescriptions thereof will be omitted.

FIGS. 7A and 7B are schematic top views of a light emitting deviceaccording to another exemplary embodiment, and FIG. 7C is across-sectional view taken along the A-A′ of FIG. 7A. FIG. 7A is a topview obtained when viewing the light emitting device from one side, forexample, a position where pads are disposed, and FIG. 7B is a top viewobtained when viewing the light emitting device from the opposing side,for example, a light emitting surface.

Referring to FIGS. 7A to 7C, a light emitting device may include asubstrate 100 and a plurality of light emitting cells LEC_1 and LEC_2disposed on the substrate 100.

The substrate 100 may have a first surface 102, on which the lightemitting cells LEC_1 and LEC_2 are disposed, and a second surface 104opposing the first surface 102. A first concave part 106 may be formedin the first surface 102 of the substrate 100, and a second concave part108 may be formed in the second surface 104 of the substrate 100. Thefirst concave part 106 may include a vertical part VL and a horizontalpart HL, and the second concave part 108 may include vertical parts VLand horizontal parts HL. The light emitting cells LEC_1 and LEC_2 may bedisposed on the first surface 102 of the substrate 100, and each of thelight emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114, and an ohmic layer 116. Thelight emitting device may further include first pads 120 electricallycoupled with first conductivity-type semiconductor layers 110 of thelight emitting cells LEC_1 and LEC_2, and second pads 130 electricallycoupled with the ohmic layers 116 of the light emitting cells LEC_1 andLEC_2. Since the substrate 100, the first concave part 106, the secondconcave part 108, the light emitting cells LEC_1 and LEC_2, the firstpads 120, and the second pads 130 are substantially the same as thesubstrate 100, the first concave part 106, the second concave part 108,the light emitting cells LEC_1 and LEC_2, the first pads 120, and thesecond pads 130 described above with reference to FIGS. 6A and 6B,repeated descriptions thereof will be omitted.

The substrate 100 may include cell areas CA, where the light emittingcells LEC_1 and LEC_2 are positioned, and a peripheral area PA excludingthe cell areas CA. Each of the cell areas CA may include a lightemitting area EA, through which light is emitted. The light emittingarea EA may be smaller than the cell area CA.

Referring to FIGS. 7A and 7C, a first light shielding layer 140, whichfills at least a portion of the first concave part 106, may be providedon the first surface 102 of the substrate 100. The first light shieldinglayer 140 may be disposed to cover a portion of the peripheral area PA,so as to expose the cell areas CA.

Referring to FIGS. 7B and 7C, a second light shielding layer 145, whichfills at least a portion of the second concave part 108, may be providedon the second surface 104 of the substrate 100. The second lightshielding layer 145 may cover the peripheral area PA and partially coverthe cell areas CA, thereby exposing light emitting areas EA. Forexample, when each cell area CA has a quadrangular structure when viewedfrom the top, each light emitting area EA may have a quadrangularstructure concentric with each cell area CA with a smaller size than thecorresponding cell area CA.

While each of the first light shielding layer 140 and the second lightshielding layer 145 is illustrated as having the structure describedabove with reference to FIG. 2B, however, in some exemplary embodiments,the first light shielding layer 140 may have at least one of thestructures of the first light shielding layer 140 illustrated in FIGS.2A, 2C to 2D, without being limited thereto.

In this case, light emitted from the light emitting cells LEC_1 andLEC_2 are radiated through the light emitting areas EA having a sizesmaller than each of the light emitting cells LEC_1 and LEC_2, and aportion of the substrate 100 excluding the light emitting areas EA isshielded by the second light shielding layer 145. As such, light emittedfrom the light emitting cells LEC_1 and LEC_2 may be emitted by beingconcentrated in the light emitting areas EA. In this manner, the lightemitting device may have an excellent contrast.

In addition, although the thickness of the substrate 100 is thin,because the first light shielding layer 140 and the second lightshielding layer 145 are formed on the first surface 102 and the secondsurface 104 of the substrate 100, respectively, it is possible toprevent the substrate 100 from being broken by an external shock andprevent the light emitting device from being damaged. Also, when thesubstrate 100 includes a glass material and the second surface 104 ofthe substrate 100 is a light extraction surface, a phenomenon thatexternal light is reflected by the second surface 104, which function asthe light extraction surface, and cause an unintended external object tobe recognized may be prevented by the second light shielding layer 145formed on the second surface 104.

According to an exemplary embodiment, rough structures PT may be formedon the second surface 104 of the substrate 100 corresponding to thelight emitting areas EA, by using a roughing process. As each of thelight emitting areas EA has the rough structure PT, light emittedthrough each light emitting area EA, which is smaller than each of thelight emitting cells LEC_1 and LEC_2, may be scattered by the roughstructure PT, such that the light extraction effect of the lightemitting device may be improved. In some exemplary embodiments, therough structures PT corresponding to the light emitting areas EA on thesecond surface 104 of the substrate 100 may be omitted.

Since the substrate 100, the first concave part 106, the second concavepart 108, the first light shielding layer 140, the second lightshielding layer 145, and the plurality of light emitting cells LEC_1 andLEC_2 illustrated in FIGS. 7A to 7C are substantially the same as thosefor the substrate 100, the concave part 106, the light shielding layer140, and the plurality of light emitting cells LEC_1 and LEC_2 describedabove with reference to FIGS. 1A to 1F and 2A to 2D, repeateddescriptions thereof will be omitted.

FIGS. 8A and 8B are schematic top views of a light emitting deviceaccording to another exemplary embodiment, and FIG. 8C is across-sectional view taken along line A-A′ of FIG. 8A. FIG. 8A is a topview obtained when viewing the light emitting device from one side, forexample, a position where pads are disposed, and FIG. 8B is a top viewobtained when viewing the light emitting device from the opposing side,for example, a light emitting surface.

Referring to FIGS. 8A to 8C, a light emitting device may include asubstrate 100 and a plurality of light emitting cells LEC_1 and LEC_2disposed on the substrate 100.

The substrate 100 may have a first surface 102, on which the lightemitting cells LEC_1 and LEC_2 are disposed, and a second surface 104opposing the first surface 102. The substrate 100 may include cell areasCA, where the light emitting cells LEC_1 and LEC_2 are positioned, and aperipheral area PA excluding the cell areas CA. Each of the cell areasCA may include a light emitting area EA. The light emitting area EA maybe smaller than the cell area CA. A first concave part 106 may be formedin the first surface 102 of the substrate 100, and a second concave part108 may be formed in the second surface 104 of the substrate 100. Thefirst concave part 106 may include a vertical part VL and a horizontalpart HL, and the second concave part 108 may include vertical parts VLand horizontal parts HL.

Since the substrate 100, the first concave part 106, and the secondconcave part 108 are substantially the same as the substrate 100, thefirst concave part 106, and the second concave part 108 described abovewith reference to FIGS. 7A to 7C, repeated descriptions thereof will beomitted.

The light emitting device may further include a first light shieldinglayer 140, which is formed in the first concave part 106, and a secondlight shielding layer 145, which is formed in the second concave part108. The first light shielding layer 140 may fill at least a portion ofthe first concave part 106, and may have the structure illustrated inFIG. 2B. The second light shielding layer 145 may fill at least aportion of the second concave part 108, and may have the structureillustrated in FIG. 2B.

While the first light shielding layer 140 and the second light shieldinglayer 145 are illustrated as having the structure illustrated in FIG.2B, however, the inventive concepts are not limited thereto. Forexample, in some exemplary embodiments, the first light shielding layer140 and the second light shielding layer 145 may have at least one ofthe structures of the first light shielding layer 140 illustrated inFIGS. 2A, 2C to 2D, without being limited thereto.

According to an exemplary embodiment, the first light shielding layer140 may include metal, such as Ti, Ni, Al, Ag, and Cr, or may include amaterial, such as a photoresist, epoxy, PDMS, and a black matrix. Thesecond light shielding layer 145 may include metal, such as Ti, Ni, Al,Ag, and Cr.

Each of the light emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114, and an ohmic layer 116. Thefirst conductivity-type semiconductor layer 110 may be an n-typesemiconductor layer, and the second conductivity-type semiconductorlayer 114 may be a p-type semiconductor layer. Alternatively, the firstconductivity-type semiconductor layer 110 may be a p-type semiconductorlayer, and the second conductivity-type semiconductor layer 114 may bean n-type semiconductor layer.

According to an exemplary embodiment, the first conductivity-typesemiconductor layer 110 of each of the light emitting cells LEC_1 andLEC_2 may be electrically coupled with the second light shielding layer145 through a through electrode VE. As described above, since the secondlight shielding layer 145 includes metal, such as Ti, Ni, Al, Ag and Cr,the second light shielding layer 145 may function as an electrode. Moreparticularly, current may be supplied to first conductivity-typesemiconductor layers 110 through the second light shielding layer 145,and the second light shielding layer 145 may function as a common pad,which supplies current to the first conductivity-type semiconductorlayers 110.

According to an exemplary embodiment, since light generated from the twoneighboring light emitting cells LEC_1 and LEC_2, for example, a firstlight emitting cell LEC_1 and a second light emitting cell LEC_2, maynot be mixed with each other due to the presence of the first lightshielding layer 140 and the second light shielding layer 145, the lightemitting device may have excellent color reproducibility. Moreover,because the first light shielding layer 140 is disposed on the firstsurface 102 of the substrate 100 and the second light shielding layer145 is disposed on the second surface 104 of the substrate 100, it ispossible to prevent the substrate 100 having a thin thickness from beingdamaged by an external shock. Further, as the second light shieldinglayer 145 includes metal, the second light shielding layer 145 mayfunction as a common pad, which supplies current to the firstconductivity-type semiconductor layers 110.

According to an exemplary embodiment, since the second light shieldinglayer 145 selectively exposes the light emitting areas EA and shieldsthe other portion as illustrated in FIG. 8B, light generated from thelight emitting cells LEC_1 and LEC_2 may be emitted by passing throughthe light emitting areas EA, each of which is smaller than thecorresponding cell area CA. As such, light generated from the lightemitting cells LEC_1 and LEC_2 may be emitted by being concentrated inthe light emitting areas EA. In this manner, the light emitting devicemay have an excellent contrast.

The light emitting device may further include pads 120, which arerespectively disposed on ohmic layers 116. Each of the pads 120 mayinclude metal, such as Ti, Ni, Al, Ag, and Cr. The pads 120 may providecurrent to the second conductivity-type semiconductor layers 114 throughthe ohmic layers 116.

In some exemplary embodiments, rough structures PT may be formed in thelight emitting areas EA of the second surface 104 of the substrate 100,which are exposed by the second light shielding layer 145. In thismanner, light emitted through each light emitting area EA, which issmaller than each of the light emitting cells LEC_1 and LEC_2, may bescattered by the rough structure PT, such that the light emitting devicemay have an improved light extraction effect.

Since the substrate 100, the first concave part 106, the second concavepart 108, the first light shielding layer 140, the second lightshielding layer 145, and the plurality of light emitting cells LEC_1 andLEC_2 illustrated in FIGS. 8A to 8C are substantially the same as thoseof the substrate 100, the first concave part 106, the second concavepart 108, the first light shielding layer 140, the second lightshielding layer 145, and the plurality of light emitting cells LEC_1 andLEC_2 described above with reference to FIGS. 7A to 7C, repeateddescriptions thereof will be omitted.

FIGS. 9A and 9B are schematic top views of a light emitting deviceaccording to an exemplary embodiment, and FIG. 9C is a cross-sectionalview taken along line A-A′ of FIG. 9A. FIG. 9A is a top view obtainedwhen viewing the light emitting device from one side, for example, aposition where pads are disposed, and FIG. 9B is a top view obtainedwhen viewing the light emitting device from the opposing side, forexample, a light emitting surface.

Referring to FIGS. 9A to 9C, a light emitting device may include asubstrate 100, a plurality of light emitting cells LEC_1 and LEC_2disposed on a first surface 102 of the substrate 100, a first pad 120and second pads 130 disposed on the first surface 102 of the substrate100 and are electrically coupled with the plurality of light emittingcells LEC_1 and LEC_2, and a light shielding layer 140 disposed on asecond surface 104 of the substrate 100 opposing the first surface 102.

The substrate 100 may include cell areas CA, where the light emittingcells LEC_1 and LEC_2 are disposed, and a peripheral area PA excludingthe cell areas CA. Each of the cell areas CA may include a lightemitting area EA, which is smaller than the corresponding cell area CA.

Each of the light emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114 and an ohmic layer 116, whichare vertically stacked. The first pad 120 may electrically couple firstconductivity-type semiconductor layers 110 in common. The first pad 120may supply current to the first conductivity-type semiconductor layers110. For example, the first pad 120 may include metal, such as Ti, Ni,Al, Ag, Cr, Au and Cu.

According to an exemplary embodiment, the first pad 120 may be disposedbetween the first conductivity-type semiconductor layers 110 and thefirst surface 102 of the substrate 100. The first pad 120 may bedisposed on the center portion of the substrate 100, cover portions ofthe cell areas CA, and expose respective light emitting areas EA. Lightgenerated from the light emitting cells LEC_1 and LEC_2 may be shielded,reflected, or absorbed at the portions of the cell areas CA covered bythe first pad 120, and may be radiated toward the substrate 100 throughthe light emitting areas EA. As such, the first pad 120 may function asa light shielding layer.

When viewed from the top, the substrate 100 may have substantially aquadrangular structure, and the light emitting cells LEC_1 and LEC_2 maybe disposed at respective corners of the substrate 100 while beingseparated from the edges of the substrate 100. For example, the firstpad 120 may have substantially a cross-shaped structure, which exposesthe respective corners of the substrate 100. In this case, the first pad120 may expose not only the light emitting areas EA but also portions ofthe substrate 100 disposed between the light emitting areas EA and therespective corners of the substrate 100. As another example, the firstpad 120 may have substantially a quadrangular structure includingopenings, which expose the light emitting areas EA. In this case, thefirst pad 120 may selectively expose only the light emitting areas EA.

The respective second pads 130 may be disposed while being brought intoelectrical contact with the respective ohmic layers 116. The second pads130 may supply current to second conductivity-type semiconductor layers114 through the ohmic layers 116.

The second surface 104 of the substrate 100 may include a concave part108, which is recessed from the second surface 104 to the inside of thesubstrate 100. The concave part 108 may include vertical parts VLextending in a first direction DR1 and are parallel to each other, andhorizontal parts HL extending in a second direction DR2 and are parallelto each other. In some exemplary embodiments, the vertical parts VL andthe horizontal parts HL of the concave part 108 may cross with eachother.

While the concave part 108 according to the illustrated exemplaryembodiment is described as having the structure described above withreference to FIG. 1C, however, in some exemplary embodiments, theconcave part 108 may have one of the structures of the concave part 108described above with reference to FIGS. 1D to 1F, without being limitedthereto.

The light shielding layer 145 may be disposed on the second surface 104of the substrate 100. According to an exemplary embodiment, the lightshielding layer 145 may include a first portion 145_1 that fills atleast a portion of the concave part 108, and second portions 145_2disposed at corners on the second surface 104 of the substrate 100,respectively, to expose the light emitting areas EA.

While the first portion 145_1 of the light shielding layer 145 accordingto the illustrated exemplary embodiment is described as having thestructure of FIG. 2A, however, in some exemplary embodiments, the lightshielding layer 145 may have one the structures of the light shieldinglayer 140 described above with reference to FIGS. 2B to 2D, withoutbeing limited thereto.

The second portions 145_2 of the light shielding layer 145 may bedisposed in correspondence to portions of the substrate 100 where thefirst pad 120 is not formed, and may expose the light emitting areas EA.Each of the second portions 145_2 may have substantially an L-shapedstructure in a plan view. According to another exemplary embodiment, asillustrated in FIG. 7B, the light shielding layer 145 may have astructure, which selectively exposes the light emitting areas EA andcovers the entirety of the other portion.

Light generated from the light emitting cells LEC_1 and LEC_2 may bereflected, shielded, or absorbed by the first portion 145_1 of the lightshielding layer 145. As such, light of the light emitting cells LEC_1and LEC_2 may be prevented from being mixed, thereby improving the colorreproducibility of the light emitting device.

The second portions 145_2 of the light shielding layer 145 may coverportions of the peripheral area PA and the cell areas CA that notcovered by the first pad 120, thereby defining the light emitting areasEA. Each of the light emitting areas EA may be smaller than each of thecell areas CA. As such, light generated from the light emitting cellsLEC_1 and LEC_2 may be emitted by being selectively concentrated throughthe light emitting areas EA. Accordingly, the light emitting device mayexhibit an excellent contrast.

Since the substrate 100, the concave part 108, the light shielding layer145, and the plurality of light emitting cells LEC_1 and LEC_2illustrated in FIGS. 9A to 9C are substantially the same as those forthe substrate 100, the second concave part 108, the second lightshielding layer 145, and the plurality of light emitting cells LEC_1 andLEC_2 described above with reference to FIGS. 8A to 8C, repeateddescriptions thereof will be omitted.

FIGS. 10A and 10B are schematic top views of a light emitting deviceaccording to another exemplary embodiment, and FIG. 10C is across-sectional view taken along line A-A′ of FIG. 10A. FIG. 10A is atop view obtained when viewing the light emitting device from one side,and FIG. 10B is a top view obtained when viewing the light emittingdevice from the opposing side.

Referring to FIGS. 10A to 10C, a light emitting device may include asubstrate 100, a plurality of light emitting cells LEC_1 and LEC_2disposed on a first surface 102 of the substrate 100, first pads 120 anda second pad 130 disposed on the first surface 102 of the substrate 100and are electrically coupled with the light emitting cells LEC_1 andLEC_2, and a light shielding layer 145 disposed on a second surface 104of the substrate 100 opposing the first surface 102.

The substrate 100 may include cell areas CA, where the light emittingcells LEC_1 and LEC_2 are disposed, and a peripheral area PA excludingthe cell areas CA. Each of the cell areas CA may include a lightemitting area EA, which is smaller than each cell area CA.

When viewed from the top, the substrate 100 may have substantially aquadrangular structure, and the light emitting cells LEC_1 and LEC_2 maybe disposed at respective corners of the substrate 100 by beingseparated from the edges of the substrate 100.

Each of the light emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114, and an ohmic layer 116, whichare vertically stacked. The first pads 120 may be electrically coupledwith respective first conductivity-type semiconductor layer 110. Thefirst pads 120 may supply current to the respective firstconductivity-type semiconductor layer 110. For example, the first pads120 may include metal, such as Ti, Ni, Al, Ag, Cr, Au, and Cu.

According to an exemplary embodiment, each of the first pads 120 may bedisposed between the corresponding first conductivity-type semiconductorlayer 110 and the first surface 102 of the substrate 100. The first pads120 may be disposed at the respective corners of the substrate 100 toexpose light emitting areas EA. For example, each of the first pads 120may have substantially an L-shaped structure in a plan view.

The first pads 120 may cover portions of the cell areas CA and exposethe light emitting areas EA. Light generated from the light emittingcells LEC_1 and LEC_2 may be shielded, reflected, or absorbed atportions of the substrate 100 covered by the first pads 120, and may beradiated toward the substrate 100 through the light emitting areas EA.As such, each of the first pads 120 may function as a light shieldinglayer.

The second pad 130 may be disposed at the center portion of thesubstrate 100. The second pad 130 may be electrically coupled with theohmic layers 116 in common, and may extend to the first surface 102 ofthe substrate 100. According to an exemplary embodiment, the lightemitting device may further include a passivation layer PVT, which isdisposed between the first conductivity-type semiconductor layers 110,active layers 112, second conductivity-type semiconductor layers 114,the ohmic layers 116, the substrate 100, and the second pad 130. Thesecond pad 130 may include metal, such as Ti, Ni, Al, Ag, Cr, Au, andCu, and the passivation layer PVT may include an insulating material,such as SiO₂ and SiN. The passivation layer PVT may include openings,which expose at least portions of the ohmic layers 116. The second pad130 may be electrically coupled with the ohmic layers 116 through theopenings.

According to an exemplary embodiment, the second pad 130 may cover thetop portions of the respective ohmic layers 116. In this case, some ofthe light emitted in all directions from the respective active layers112 may be reflected toward the substrate 100 by the second pad 130.

According to an exemplary embodiment, the respective first pads 120 mayoverlap with portions of the second pad 130. The respective first pads120 may cover the portions of the cell areas CA and expose the lightemitting areas EA, and the second pad 130 may cover the cell areas CAincluding the light emitting areas EA.

The light shielding layer 145 may fill at least a portion of a concavepart 108, which is formed in the second surface 104 of the substrate100. While the concave part 108 is illustrated as having the structuredescribed above with reference to FIG. 1C, however, in some exemplaryembodiments, the concave part 108 may have one the structures of theconcave part 106 described above with reference to FIGS. 1D, 1E and 1F,without being limited thereto. Also, while the light shielding layer 145is illustrated as having the structure of FIG. 2B, however, in someexemplary embodiments, the light shielding layer 145 may have one of thestructures of the light shielding layer 140 described above withreference to FIGS. 2A, 2C and 2D, without being limited thereto.

According to an exemplary embodiment, the light shielding layer 145 mayfill the concave part 108 while covering a portion of the second surface104 of the substrate 100. The light shielding layer 145 may be disposedat the center area of the second surface 104 of the substrate 100. Thelight shielding layer 145 may be disposed to expose the light emittingareas EA and correspond to an area where the first pads 120 are notdisposed. For example, the light shielding layer 145 may havesubstantially a cross-shaped structure to expose the light emittingareas EA. The light shielding layer 145 may include metal, such as Ti,Ni, Al, Ag, and Cr, or may include a material, such as a photoresist,epoxy, PDMS, and a black matrix.

Light generated from the light emitting cells LEC_1 and LEC_2 may bereflected, shielded, or absorbed by the light shielding layer 145, andlight of the light emitting cells LEC_1 and LEC_2 may be prevented frombeing mixed, thereby improving the color reproducibility of the lightemitting device. The light shielding layer 145 may cover portions of theperipheral area PA and the cell areas CA, which are not covered by thefirst pads 120, thereby defining the light emitting areas EA. Each ofthe light emitting areas EA may be smaller than each cell area CA. Assuch, light generated from the light emitting cells LEC_1 and LEC_2 maybe emitted by being selectively concentrated through the light emittingareas EA. In this manner, the light emitting device may exhibitexcellent contrast.

The light emitting device may further include first solders SD1, whichare electrically coupled with the first pads 120, respectively, on thefirst pads 120, and a second solder SD2, which is electrically coupledwith the second pad 130 on the second pad 130.

Since the substrate 100, the concave part 108, the light shielding layer145, and the plurality of light emitting cells LEC_1 and LEC_2illustrated in FIGS. 10A to 10C are substantially the same as those ofthe substrate 100, the concave part 108, the light shielding layer 145,and the plurality of light emitting cells LEC_1 and LEC_2 describedabove with reference to FIGS. 9A to 9C, repeated descriptions thereofwill be omitted.

FIG. 11A is a schematic top view of a light emitting device according toanother exemplary embodiment, and FIG. 11B is a cross-sectional viewtaken along line A-A′ of FIG. 11A. FIG. 11A is a top view obtained whenviewing the light emitting device from one side, for example, a positionwhere pads are disposed. Since a top view obtained when viewing thelight emitting device from the opposing side, for example, a lightemitting surface, is substantially the same as FIG. 10B, the top view ofthe opposing side may be referenced to FIG. 10B.

Referring to FIGS. 10B, 11A and 11B, a light emitting device may includea substrate 100, a plurality of light emitting cells LEC_1 and LEC_2disposed on a first surface 102 of the substrate 100, first pads 120 andsecond pads 130 disposed on the first surface 102 of the substrate 100and are electrically coupled with the light emitting cells LEC_1 andLEC_2, a first light shielding layer 140 disposed on the first surface102 of the substrate 100 between the light emitting cells LEC_1 andLEC_2, and a second light shielding layer 145 disposed on a secondsurface 104 of the substrate 100 opposing the first surface 102.

The substrate 100 may include cell areas CA, where the light emittingcells LEC_1 and LEC_2 are disposed, and a peripheral area PA excludingthe cell areas CA. Each of the cell areas CA may include a lightemitting area EA, which is smaller than each cell area CA.

Each of the light emitting cells LEC_1 and LEC_2 may include a firstconductivity-type semiconductor layer 110, an active layer 112, a secondconductivity-type semiconductor layer 114, and an ohmic layer 116, whichare vertically stacked. The first pads 120 may be disposed between thecorresponding first conductivity-type semiconductor layer 110 and thesubstrate 100. Each of the first pads 120 may be brought into electricalcontact with the corresponding first conductivity-type semiconductorlayer 110. According to an exemplary embodiment, the substrate 100 mayhave substantially a quadrangular structure. When the light emittingcells LEC_1 and LEC_2 are respectively disposed at the corners of thesubstrate 100, the first pads 120 may be respectively disposed at thecorners, and may respectively expose light emitting areas EA. Each ofthe first pads 120 may include metal, such as Ti, Ni, Al, Ag, Cr, Au,and Cu.

The second pads 130 may be electrically coupled with the correspondingohmic layer 116. In some exemplary embodiments, a passivation layer PVTmay be further included, which is disposed between the firstconductivity-type semiconductor layers 110, active layers 112, secondconductivity-type semiconductor layers 114, the ohmic layers 116, thesubstrate 100, and the second pads 130. Each of the second pads 130 mayinclude metal, such as Ti, Ni, Al, Ag, Cr, Au, and Cu, and thepassivation layer PVT may include an insulating material, such as SiO₂and SiN. The passivation layer PVT may include openings, whichrespectively expose at least portions of the ohmic layers 116. Therespective second pads 130 may be electrically coupled with therespective ohmic layers 116 through the openings.

According to an exemplary embodiment, the respective second pads 130 maycover the top portions of the respective ohmic layers 116. In this case,some of lights emitted in all directions from the respective activelayers 112 may be reflected toward the substrate 100 by the second pads130.

According to an exemplary embodiment, the respective first pads 120 mayoverlap with the respective second pads 130. The respective first pads120 may cover portions of the cell areas CA and expose the lightemitting areas EA, and the respective second pads 130 may cover therespective cell areas CA including the respective light emitting areasEA.

The first light shielding layer 140 may fill at least a portion of afirst concave part 106, which is formed in the first surface 102 of thesubstrate 100. For example, the first light shielding layer 140 mayinclude metal, such as Ti, Ni, Al, Ag, and Cr, or may include amaterial, such as a photoresist, epoxy, PDMS, and a black matrix.

While the first concave part 106 is illustrated as having the structuredescribed above with reference to FIG. 1C, however, in some exemplaryembodiments, the concave part 106 may have one the structures of thefirst concave part 106 described above with reference to FIGS. 1D to 1F,without being limited thereto. Also, while the first light shieldinglayer 140 is illustrated as having the structure of FIG. 2B, however, insome exemplary embodiments, the first light shielding layer 140 may haveone of the structures of the light shielding layer 140 described abovewith reference to FIGS. 2A, 2C and 2D, without being limited thereto.

Since the second light shielding layer 145 is substantially the same asthe second light shielding layer 145 described above with reference toFIGS. 10A to 10C, repeated descriptions thereof will be omitted.

Light generated from the light emitting cells LEC_1 and LEC_2 may bereflected, shielded, or absorbed by the first light shielding layer 140and the second light shielding layer 145, and thus, light of the lightemitting cells LEC_1 and LEC_2 may be prevented from being mixed,thereby improving the color reproducibility of the light emittingdevice. The second light shielding layer 145 may cover portions of theperipheral area PA and the cell areas CA, which are not covered by thefirst pads 120, thereby defining the respective light emitting areas EA.Each of the light emitting areas EA may be smaller than each cell areaCA. As such, light generated from the light emitting cells LEC_1 andLEC_2 may be emitted by being selectively concentrated through the lightemitting areas EA. Therefore, the light emitting device may exhibit anexcellent contrast.

Since the substrate 100, the first concave part 106, the second concavepart 108, the first light shielding layer 140, the second lightshielding layer 145, the plurality of light emitting cells LEC_1 andLEC_2, the first pads 120, and the second pads 130 illustrated in FIGS.11A and 11B are substantially the same as those for the substrate 100,the first concave part 106, the second concave part 108, the first lightshielding layer 140, the second light shielding layer 145, the pluralityof light emitting cells LEC_1 and LEC_2, the first pads 120, and thesecond pads 130 described above with reference to FIGS. 6A to 6C,repeated descriptions thereof will be omitted.

Hereinafter, a method for manufacturing a light emitting deviceaccording to an exemplary embodiment will be described. In particular, amethod for manufacturing the light emitting device illustrated in FIGS.7A to 7C will be described as an example.

FIGS. 12A to 16A are schematic top views illustrating a method formanufacturing a light emitting device according to an exemplaryembodiment, and FIGS. 12B to 16B are cross-sectional views taken alongthe lines A-A′ of FIGS. 12A to 16A.

Referring to FIGS. 12A and 12B, cells may be formed on a first surface102 of a substrate 100.

A first conductivity-type semiconductor layer 110, an active layer 112,and a second conductivity-type semiconductor layer 114 may be formed onthe first surface 102 of the first substrate 100 by using a growingmethod, such as metal organic chemical vapor deposition (MOCVD),molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HYPE), andmetal-organic chloride (MOC).

Then, an ohmic layer 116 may be formed on the second conductivity-typesemiconductor layer 114 by using a deposition process.

By etching the ohmic layer 116, the second conductivity-typesemiconductor layer 114, and the active layer 112, mesa structuresexposing portions of the first conductivity-type semiconductor layer 110may be formed. After forming the mesa structures, the mesa structuresmay have sloped sidewalls through a reflow process, for example.

By patterning the first conductivity-type semiconductor layer 110, aplurality of light emitting cells LEC_1 and LEC_2 may be formed.

In some exemplary embodiments, in order to form light emitting cellsLEC_1 and LEC_2, after an ohmic layer 116 is formed on a first surfaceof a substrate 100, semiconductor layers formed on other substrates maybe sequentially bonded to the ohmic layer 116, which may then bepatterned to form the light emitting cells each including a first lightemitting part LEC_1_1 or LEC_2_1, a second light emitting part LEC_1_2or LEC 2_2, and a third light emitting part LEC_1_3 or LEC_2_3.

Referring to FIGS. 13A and 13B, first pads 120 electrically coupled withfirst conductivity-type semiconductor layers 110, respectively, exposedby the mesa structures, and second pads 130 electrically coupled withohmic layers 116, respectively, may be formed.

A pad layer may be conformally formed on the substrate 100, which isformed with the plurality of light emitting cells LEC_1 and LEC_2,through a deposition process generally known in the art. The pad layermay include at least one of Ti, Ni, Al, Ag, Cr, Au, and Cu. By patteringthe pad layer, the first pads 120 may be respectively formed on thefirst conductivity-type semiconductor layers 110, and the second pads130 may be respectively formed on the ohmic layers 116.

Referring to FIGS. 14A and 14B, by polishing a second surface 104 of thesubstrate 100 opposing the first surface 102 through a process, such aschemical mechanical polishing or others, the substrate 100 may be formedthin.

Referring to FIGS. 15A and 15B, a first concave part 106 may be formedin the first surface 102 of the substrate 100. For example, the firstconcave part 106 may be formed in the first surface 102 of the substrate100 by a laser process or an etching process.

A first light shielding layer 140, which fills at least a portion of thefirst concave part 106 may be formed on the first surface 102 of thesubstrate 100 by a process, such as plating, corrosion, deposition,taping, painting, and screen printing. The first light shielding layer140 may include metal, such as Ti, Ni, Al, Ag, and Cr, or may include amaterial, such as a photoresist, epoxy, PDMS, and a black matrix.

According to an exemplary embodiment, through the processes of FIGS. 12Ato 15A and 12B to 15B, the light emitting device illustrated in FIGS. 1Aand 1B may be formed.

Referring to FIGS. 16A and 16B, a second concave part 108 may be formedin the second surface 104 of the substrate 100. For example, the secondconcave part 108 may be formed in the second surface 104 of thesubstrate 100 by a laser process or an etching process.

A second light shielding layer 145, which fills at least a portion ofthe second concave part 108 and includes openings exposing lightemitting areas EA of the substrate 100, may be formed on the secondsurface 104 of the substrate 100 by a process, such as plating,corrosion, deposition, taping, painting, and screen printing. The secondlight shielding layer 145 may include metal, such as Ti, Ni, Al, Ag, andCr, or may include a material, such as a photoresist, epoxy, PDMS, and ablack matrix.

While the second concave part 108 and the second light shielding layer145 are described as being formed after forming the first concave part106 and the first light shielding layer 140, however, in some exemplaryembodiments, the first light shielding layer 140 and the second lightshielding layer 145 may be formed after forming the first concave part106 and the second concave part 108.

In this process, when the second light shielding layer 145 is formed tobe retained only in the second concave part 108 through the processes ofFIGS. 12A to 16A and 12B to 16B, the light emitting device illustratedin FIGS. 6A and 6B may be formed.

In some exemplary embodiments, referring back to FIGS. 7A and 7B, roughstructures PT may be formed on the second surface 104 of the substrate100 corresponding to the light emitting areas EA. For example, the roughstructures PT may be formed on the second surface 104 of the substrate100 by using a process, such as sandblasting, etching, and grinding.

Hereafter, a method for manufacturing a light emitting device accordingto another exemplary embodiment will be described. In particular, amethod for manufacturing the light emitting device illustrated in FIGS.10A to 10C will be described as an example.

FIGS. 17A to 19A are schematic top views illustrating a method formanufacturing a light emitting device according to another exemplaryembodiment, and FIGS. 17B to 19B are cross-sectional views taken alongthe lines A-A′ of FIGS. 17A to 19A.

Referring to FIGS. 17A and 17B, circuit patterns including first pads120 may be formed on a first surface 102 of a substrate 100.

The substrate 100 may include a plurality of cell areas CA and aperipheral area PA excluding the cell areas CA. The cell areas CA mayinclude light emitting areas EA, each of which is smaller than each cellarea CA.

The first pads 120 may be disposed while exposing the light emittingareas EA. For example, when the substrate 100 has substantially aquadrangular structure, the first pads 120 may be disposed at therespective corners of the substrate 100. In order to expose the lightemitting areas EA, each of the first pads 120 may have substantially anL-shaped structure in a plan view.

Referring to FIGS. 18A and 18B, after forming a first conductivity-typesemiconductor layer 110, an active layer 112, a second conductivity-typesemiconductor layer 114, and an ohmic layer 116 on the first surface 102of the substrate 100 on which the circuit patterns including the firstpads 120 are formed, a plurality of light emitting cells LEC_1 and LEC_2may be formed in the respective cell areas CA by etching, as shown inFIGS. 12A and 12B.

According to an exemplary embodiment, first conductivity-typesemiconductor layer 110 of the respective light emitting cells LEC_1 andLEC_2 may be disposed while being brought into electrical contact withthe first pads 120. Each of the first pads 120 may include at least oneof Ti, Ni, Al, Ag, Cr, Au, and Cu.

According to an exemplary embodiment, the respective first pads 120 mayfunction as a light shielding layer by selectively exposing the lightemitting areas EA and covering the other portion.

Referring to FIGS. 19A and 19B, a passivation layer PVT may beconformally formed on the light emitting cells LEC_1 and LEC_2, and, byetching the passivation layer PVT, openings exposing portions of ohmiclayers 116 may be formed. A second pad 130, which fills the openings andextends onto the first surface 102 of the substrate 100, may be formedon the passivation layer PVT. The second pad 130 may be electricallycoupled with the ohmic layers 116 in common.

According to an exemplary embodiment, the second pad 130 may be formedwhile covering the top surfaces of the respective ohmic layers 116. Inthis manner, as the second pad 130 covers the top surfaces of therespective ohmic layers 116, light generated from active layers 112 maybe reflected toward the substrate 100. While the second pad 130 maycover the light emitting areas EA on the ohmic layers 116, the secondpad 130 may expose the respective light emitting areas EA on the firstsurface 102 of the substrate 100.

Referring back to FIGS. 10A to 10C, a concave part 108 may be formed ona second surface 104 of the substrate 100 opposing the first surface102, by using a laser process or an etching process. A light shieldinglayer 145, which fills at least a portion of the concave part 108 andexposes the respective light emitting areas EA, may be formed on thesecond surface 104 of the substrate 100. The light shielding layer 145may include metal, such as Ti, Ni, Al, Ag, and Cr, or may include amaterial, such as a photoresist, epoxy, PDMS, and a black matrix.

By the first pads 120 formed on the first surface 102 of the substrate100 and the light shielding layer 145 formed on the second surface 104of the substrate 100, the light emitting areas EA may be defined.

In the light emitting device according to exemplary embodiments, byforming a concave part in a substrate including a plurality of lightemitting cells and disposing a light shielding layer, which fills atleast partially the concave part, light generated from neighboring lightemitting cells may be shielded, absorbed, or reflected by the lightshielding layer and may not exert an influence to each other. In thismanner, a color mixing between adjacent light emitting cells may beprevented, thereby improving the color reproducibility of the lightemitting device.

Also, by disposing light shielding layers on both surfaces of thesubstrate, the light emitting device including the substrate having athin thickness may be prevented from being damaged by an external shock.

Moreover, by shielding a portion of a cell area where each lightemitting cell is disposed, a light emitting area may be formed to besmaller than the cell area. As such, light passing through the lightemitting area and emitted from the light emitting cell may be moreconcentrated, thereby improving the contrast of the light emittingdevice.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. A light emitting device comprising: a substratehaving a first surface and a second surface opposing the first surface,at least one of the first and second surfaces having a concave partextending to the inside of the substrate; a plurality of light emittingcells disposed on the first surface of the substrate; and a lightshielding layer filling at least a portion of the concave part anddisposed between the plurality of light emitting cells.
 2. The lightemitting device according to claim 1, wherein at least one of the lightemitting cells has a first light emitting part, a second light emittingpart, and a third light emitting part vertically stacked one overanother.
 3. The light emitting device according to claim 2, furthercomprising a common pad, a first pad, a second pad, and a third paddisposed on the at least one light emitting cell, wherein the common padis electrically connected to the first, second, and third light emittingparts in common, and the first, second, and third pads are electricallyconnected to the first, second, and third light emitting parts,respectively.
 4. The light emitting device according to claim 1, whereinthe light shielding layer includes at least one of Ti, Ni, Al, Ag, Cr, aphotoresist, epoxy, PDMS, and a black matrix.
 5. The light emittingdevice according to claim 1, wherein: the light shielding layer isdisposed on the first surface of the substrate; and the light shieldinglayer is disposed between the light emitting cells on the first surfaceof the substrate, and has a top surface coplanar with a top surface ofeach of the light emitting cells.
 6. The light emitting device accordingto claim 5, further comprising pads disposed on the light shieldinglayer and electrically coupled with the light emitting cells,respectively.
 7. The light emitting device according to claim 5, furthercomprising: an insulating layer disposed on the light shielding layer;through electrodes passing through the insulating layer and the lightshielding layer, and electrically coupled with the light emitting cells,respectively; and pads disposed on the insulating layer and electricallycoupled with the through electrodes.
 8. The light emitting deviceaccording to claim 1, wherein: the concave part includes a first concavepart extending from the first surface of the substrate to the inside ofthe substrate, and a second concave part extending from the secondsurface of the substrate to the inside of the substrate; and the lightshielding layer includes a first light shielding layer filling at leasta portion of the first concave part and a second light shielding layerfilling at least a portion of the second concave part.
 9. The lightemitting device according to claim 8, wherein one end of the first lightshielding layer and one end of the second light shielding layer overlapwith each other.
 10. The light emitting device according to claim 8,wherein: the first light shielding layer includes a vertical partextending along a first direction and a horizontal part extending alonga second direction crossing the first direction; and the second lightshielding layer includes a plurality of vertical parts extending alongthe first direction and parallel to each other, and a plurality ofhorizontal parts extending along the second direction.
 11. The lightemitting device according to claim 10, wherein: the vertical part of thefirst light shielding layer is disposed between the vertical parts ofthe second light shielding layer; and the horizontal part of the firstlight shielding layer is disposed between the horizontal parts of thesecond light shielding layer.
 12. The light emitting device according toclaim 8, wherein: the substrate includes cell areas in which theplurality of light emitting cells are disposed, and a peripheral areaadjacent to the cell areas; the cell areas include light emitting areasdefined by the first light shielding layer and the second lightshielding layer, respectively; and each light emitting area is smallerthan each cell area.
 13. The light emitting device according to claim12, wherein portions of the substrate corresponding to the lightemitting areas have a surface roughness.
 14. The light emitting deviceaccording to claim 1, further comprising through electrodes passingthrough the substrate and electrically coupling the light shieldinglayer and the light emitting cells, wherein the light shielding layer isdisposed on the second surface of the substrate.
 15. The light emittingdevice according to claim 14, wherein the light shielding layer includesat least one of Ti, Ni, Al, Ag, and Cr.
 16. The light emitting deviceaccording to claim 1, further comprising a pad disposed between thefirst surface of the substrate and the light emitting cells, andelectrically coupled with the light emitting cells.
 17. The lightemitting device according to claim 1, wherein: the substrate includescell areas in which the plurality of light emitting cells are disposed,and a peripheral area adjacent to the cell areas; the cell areas includelight emitting areas defined by the light shielding layer, respectively;and each light emitting area is smaller than each cell area.
 18. Thelight emitting device according to claim 17, wherein portions of thesubstrate corresponding to the light emitting areas have a surfaceroughness.
 19. The light emitting device according to claim 1, whereinthe concave part has at least one of substantially a V-shaped structure,substantially a polygonal structure in which the first surface or thesecond surface of the substrate is opened, and substantially a U-shapedstructure.
 20. The light emitting device according to claim 1, whereinthe light shielding layer fills at least a portion of the concave partand extends to the first surface or the second surface of the substrate.